1) Field of the Invention
The invention relates to surgical systems applying thermal energy to biological tissue to modify the characteristics of the tissue. More particularly, the invention is directed to electrosurgical probes utilizing radio frequency (RF) energy to cut, coagulate, and/or ablate the tissue during a medical procedure for treatment and therapy.
2) Discussion of Related Art
Arthroscopic surgery is becoming increasingly popular, because it generally does less damage, is less invasive, and is safer than open procedures, and produces less scarring in and around joints. This type of surgery further results in a faster healing response and a quicker return of the patient to full productivity while reducing costs of open surgical procedures.
Arthroscopic surgery is usually performed with an electrosurgical instrument having a handle, a rigid elongated probe extending from the handle, and an electrode on a tip of the probe. A surgeon, holding the handle, inserts the tip into a body of a patient and positions the tip adjacent to a surgical site. RF current is then provided to the electrode to heat a fluid in an area adjacent to the tip and the surgical site.
A problem with an electrosurgical instrument of this kind is that the temperature of the electrode tends to fluctuate as a liquid circulates over the surgical site and over the electrode. What is needed is an electrosurgical instrument of this kind having a probe tip with a more stable temperature.
According to one aspect of the invention, an electrosurgical instrument is provided which includes a holding formation, a probe shaft, an electric conductor, and a probe tip. The probe shaft is secured to the holding formation and has an elongated section extending therefrom. The electric conductor extends along the elongated section. The probe tip is located on a distal end of the probe shaft opposing the holding formation. The probe tip defines at least a first volatization chamber with a mouth out of the probe tip. The probe tip includes at least one electrode, to which RF current is provided through the electric conductor. The electrode heats an area adjacent to the probe tip. The electrode also heats a liquid in the first volatization chamber to evaporate the liquid into a vapor pocket that ejects from the first volatization chamber through the mouth out of the probe tip.
The holding formation may be a handle.
The probe shaft may be substantially rigid to allow a surgeon to move the probe tip into position without a guide.
The electric conductor may be attached to the electrode.
An inner surface of the electrode may define the volatization chamber.
Preferably, at least one cross-section through the probe tip and the volatization chamber shows no openings from the volatization chamber out of the probe tip.
The electrode may have an exposed outer surface around the volatization chamber. The exposed outer surface may entirely surround the volatization chamber.
The electrode may have a front face around the mouth. The front face may entirely surround the mouth.
The volatization chamber may have a larger cross-sectional area than the mouth.
The electrode may be a power electrode, and the probe tip may further include a ground electrode electrically connected to the power electrode through more of the liquid.
The electrosurgical instrument may further include a ground conductor extending along the elongated section and electrically attached to the ground electrode.
The electrosurgical instrument may further include a thermocouple attached to the probe tip, and a thermocouple wire extending from the thermocouple along the elongated section.
The probe tip may have at least a second volatization chamber therein. The electrode may heat more of the liquid in the second volatization chamber. The second volatization chamber may have a separate mouth out of the probe tip than the first volatization chamber. The second volatization chamber may be a ring around the first volatization chamber.
According to another aspect of the invention, an electrosurgical instrument is provided having a probe tip including an electrode to which current is provided through an electric conductor, the electrode having an exposed face with at least a first recessed volatization chamber formed therein.
According to another aspect of the invention, a method of treating a surgical site within a body of a patient is provided. A probe tip is inserted into a surgical port formed in the body of the patient until the probe tip is positioned adjacent to the surgical site. The surgical port is at least partially filled with a liquid. The liquid enters the volatization chamber in the probe tip. RF current is provided to the electrode. The electrode heats an area adjacent to the probe tip. The electrode also heats the liquid in the volatization chamber. The liquid in the volatization chamber evaporates into a vapor pocket which ejects from a mouth of the volatization chamber out of the probe tip.
The vapor pocket is preferably contained in the volatization chamber for a period of time, to allow for growth of the vapor pocket.